This invention relates generally to a roadway reflector, and more particularly, to a reflective pavement marker for delineating traffic lanes and other areas on roadways, parking lots or the like.
The advantages of roadway lane markers to delineate traffic paths for drivers are self evident particularly from a safety perspective to advise drivers of the lane. Reflective paving markers are more desirable than painted dividing lines between traffic lanes or the like because such reflective markers are more visible to a driver over a greater distance and will function better in many instances where painted traffic lines are seen by a driver only with much difficulty such as on wet roadways, snow covered roadways or in foggy driving conditions. Further, many roadway markers provide an audible and/or tactile signal to the driver whose vehicle contacts the marker.
Thus, in order to overcome the shortcomings of painted traffic lines, roadway markers have been used. Typically, the roadway marker includes a reflective element to re-direct incident light from the head lamps of a driver's vehicle or oncoming vehicles and thereby advise the driver of the boundaries of the traffic lanes. One type of known roadway marker is surface mounted on the roadway and secured directly to the upper surface of the roadway. Surface mounted markers are more widely utilized in warmer climates where the markers would not be subject to the sheering effects of a snow plow blade. Alternatively, reflectors embedded in the roadway have found application in many areas. Typically, the physical location of embedded markers makes them more suitable for roadways subject to more sever weather conditions.
One shortcoming of many reflectors or markers is that the snow plow generally pulls the surface mounted reflector unit or embedded reflector from the road and, in most cases, also rips away subjacent and/or adjacent surface road material. Not only is the reflector itself destroyed or damaged so as to require replacement, but as a part of the replacement process, the road surface material ripped away must be repaired or restored. Thus, these devices are not cost effective where snow plowing is necessary to maintain the road clear.
In order to withstand the forces of oncoming snow plow blades and vehicular traffic, a variety of retractable roadway reflectors or markers have been developed. The retractable reflector or marker, although it typically protrudes above the road surface, may be depressed by the blade of a snow plow or vehicle tire. Such markers have incorporated conical springs for biasing the reflector upwardly or foam rubber cells for facilitating the depression and rebounding action of the reflector. However, the effects of dirt, grime, foreign debris, freezing and melting water, snow, rainwater and forces associated with road traffic all detrimentally effect the long term utility of known retractable reflectors. Still other retractable reflectors cannot withstand the scraping effect of the snow plow blades or other items passing over the reflector.
A significant disadvantage of known pavement markers is the tendency for the reflector to become damaged and require repair. Roadway reflectors or markers used in the past require removal of the entire assembly from the roadway to effect a repair. This proves to be very disruptive to traffic, time consuming and, as a result, costly.
Furthermore, roadway reflectors which have proven to be durable and reliable in use typically are very expensive to manufacture and/or install in the roadway. Due to the very large number of reflectors required to delineate traffic lanes for the hundreds of thousands miles of roadways both in existence and under construction, the unit cost for each roadway reflector must be minimized to offer an economically viable safety measure. Additionally, the installation procedures for a roadway marker must be simple, efficient and quickly accomplished in order to contribute to the economic feasibility of the unit.